Tracking the location or position of a body that can move in unknown directions over a considerable range of territory has been a concern for a number of years. The term “body” is defined broadly, meaning any organic or inorganic object whose movement or position may suitably be evaluated relative to its environment in accordance with the principles hereof. The term “environment” is defined broadly as conditions and influences that define, at least in part, the physical system in which the body is located.
In the past, locating systems were proposed that employed conventional wireless technology, but which tended to be cumbersome, bulky, expensive, and lack robustness, or all of the above. With the deployment of the global positioning system (GPS), it is now possible to provide relatively inexpensive location systems for determining body location. Such systems have been utilized, for example, on trucks to provide location information for companies having large fleets of trucks in use at any one particular time. The position of each individual truck may therefore be tracked.
Conventional GPS devices have disadvantages, including relative slowness in acquiring location data, being strongly dependent upon the target body being in an open area where it is in a line-of-sight position to the GPS satellites, and consuming a relatively large amount of electrical power during the period in which the location information is being acquired from the GPS satellites.
The inventor hereof disclosed various methodologies for an improved object locator system in the following United States Patents:    1) U.S. Pat. No. 6,518,919, entitled “Mobile Object Locator”;    2) U.S. Pat. No. 6,480,147, entitled “Portable Position Determining Device”;    3) U.S. Pat. No. 6,441,778, entitled “Pet Locator”;    4) U.S. Pat. No. 6,421,001, entitled “Object Locator”;    5) U.S. Pat. No. 6,236,358, entitled “Mobile Object Locator” and    6) U.S. Pat. No. 6,172,640, entitled “Pet Locator”.
These patents disclose an object locator system that requests and obtains information about the location of a mobile object, having attached thereon a lightweight object locator that is operable in a region served by a two-way paging system and a global positioning system. The object locator may be activated selectively to conserve power or enabled to respond only when beyond or within a defined boundary. These patents also teach that the object locator system provides the location information in several forms.
However, the methodologies disclosed in these patents fail to include the robustness necessary to track groups of bodies/objects that are related, permanently or temporarily, within one or more environments. Further, these methodologies fail to understand the complex relationships between related bodies/objects, whether such relationships are hierarchical or otherwise. Further yet, these methodologies fail to adequately address continued (though reduced) line-of-sight and power management issues.
Therefore, there is a need in the art for an improved system for gathering the location information of one or more tracked objects.